The good news for Wii players hoping to feel the burn with assistance from their console is the system comes with a free game that researchers found more effective than the $100 Wii Fit:

Researchers found that in all cases, performing an actual exercise activity rather than Wii Fit’s virtual approximation resulted in “significantly higher” caloric expenditure. The Rhythm Boxing activity, in particular, burned one-third of the calories expended per minute of traditional boxing.

“While we found that playing the Wii Fit burns twice as many calories as a sedentary video game,” said ACE’s chief science officer Cedric X. Bryant, “the outcome of the study suggests that Wii Sports, the Wii’s suite of exergames that includes tennis, boxing, golf and bowling, is a better option and more capable of helping consumers meet minimum intensity guidelines for exercise.”

I’ve found Wii Fit’s most effective weight-loss tool to be its fattening/thinning of your Mii avatar depending on your body mass index. The game also passive-aggressively scolds you when you gain weight, making you provide a reason for your piggishness. You think twice about eating those fries when you remember you’ve got to answer to Wii Fit in the morning. But yeah, it sucks as exercise.